B. Berkalp et al., EFFECTS OF PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY ON LATE POTENTIALS AND HIGH-FREQUENCY MID-QRS POTENTIALS, Cardiology, 85(3-4), 1994, pp. 216-221
The high frequency mid-QRS potentials and late potentials are importan
t in coronary artery disease because they are related to the extent of
ischemia and prognosis. In this study, the effects of successful perc
utaneous transluminal coronary angioplasty (PTCA) on these potentials
were evaluated. Twenty-four patients with coronary artery disease (age
d 34-67 years, 5 women, 19 men) were examined. Eight of these patients
had a history of myocardial infarction (4 anterior, 3 inferior, 1 ant
erior and inferior). Signal averaged ECG was recorded at 40- to 250-Hz
frequency ranges for late potentials and 150- to 250-Hz frequency ran
ges for mid-QRS potentials before PTCA, and they were repeated 1 month
later. The QRS duration (107.7 +/- 9.8 to 105.3 +/- 9.3 ms, p < 0.000
1) root-mean-square voltage (39.4 +/- 20.1 to 47.7 +/- 22.2 mu V, p <
0.00001) and low amplitude signal duration (30.7 +/- 9.9 to 27.7 +/- 9
.3 ms, p < 0.001) showed significant changes in 40- to 250-Hz ranges b
efore and after PTCA. The same results were also obtained in the 150-
to 250-Hz frequency ranges: the QRS duration decreased (90.9 +/- 9.8 t
o 86.5 +/- 9.1 ms, p < 0.005) and the root-mean-square voltage increas
ed (5.5 +/- 1.6 to 6.1 +/- 1.8 mu V, p < 0.00001). Thus, successful PT
CA causes improvement in late potential parameters, so the risk of mal
ign arrhythmia that affects the prognosis can be reduced. Additionally
, the increase in high frequency mid-QRS potentials shows the decrease
in the ischemia after PTCA.